题解 | #求解立方根#

#include <stdio.h>

double cube_root(double d, double init, double max)
{
   double i, s = 0.001;

   for (i = init; i <= max; i += s)
   {
      if (i * i * i >= d)
      {
         break;
      }
   }

   return i;
}

int main()
{
   double d;

   scanf("%lf", &d);

   if (d >= 1)
   {
      printf("%.1f", cube_root(d, 0, d));
   }
   else if (d >= 0)
   {
      printf("%.1f", cube_root(d, d, 1));
   }
   else if (d >= -1)
   {
      printf("%.1f", -1 * cube_root(d * -1, d * -1, 1));
   }
   else
   {
      printf("%.1f", -1 * cube_root(d * -1, 0, d * -1));
   }

   return 0;
}